The invention is based on an electric potentiometer as generally defined hereinafter. A potentiometer is already known which is disposed on an air flow rate meter and serves to regulate the fuel supply to an internal combustion engine, and in which the metal support points extend crosswise to the contact track of the pickup and over the entire width of the resistance pad. An error in the course of the output voltage occurs, because as the wiper passes over the width of the support points the voltage does not vary. Furthermore, the slight elevation in the resistance pad at each support point results in increased wear of resistance pad material at these points.